A technology of travelling a moving object such as a robot is to develop ability of stably travelling the moving object to a desired destination while autonomously adapting to any environment. Recently, the technology for travelling the moving object may be mainly divided into a position estimation technology and a map creating technology. The position estimation technology is a technology capable of applying for a person as well as a moving object. Therefore, numerous researches into the position estimation technology have been conducted.
Particularly, a global positioning system (GPS) based position estimation technology in an outdoor environment has been dominantly used in various moving object travelling technologies. A navigation device informing a user of a travel route at the time of driving of a car may be mounted and used in most of cars due to the development of GPS technology. In the case of a normal GPS system, there is an error of several meters in accuracy. Even though a high cost differential GPS system has an error within several centimeters, it has a difficulty in being widely used due to the high cost.
Therefore, in the technology for travelling the moving object such as a robot, autonomously travelling of the moving object only by the GPS position estimation system having the error over several meters is significantly dangerous because the moving object may impact on a surrounding pedestrians.
In the case of a car navigation device, a person drives a car while directly seeing a generated route. That is, a person having superior estimation ability and inference ability as compared to an existing moving object such as a robot drives the car, such that the person can quickly react to a dangerous situation. On the other hand, it is very difficult to allow the moving object such as the robot to autonomously travel on the road only by the position estimation system having an error over several meters.
Therefore, a laser scanner, an image estimation camera, and the like, have been generally used together with the GPS position estimation system. However, since the laser scanner and the image camera additionally mounted on the moving object such as the robot are very expensive, in view of cost, it find it hard to widely use the moving object including the laser scanner and the image camera for the life of the human.
The demand for a method for allowing the moving object such as the robot to accurately measure a position even outdoors by combining a cheap image estimation camera with map information without using an expensive sensor in consideration of cost has increased. In the technology of travelling the moving object, a map may also be used as an important medium for current position identification, destination transfer, or the like, between the user and the moving object.
Therefore, a need exists for a technology of accurately building a map for outdoor navigation of a moving object such as a robot, that is, information required for navigation of the moving object such as the robot at a minimum cost.